Improvement in expanding cylinders



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` IMPROVEMENT IN EXPANDING GYLINDBRS.

SPECIFICATION- 'TO ALL WHOM IT MAY CONCERN: p

Be it known that I, l?. MALTBY, of Kent, in the county of Portage, and State of Ohio, have invented a` certain new and improved Chucking Mandrel; and' I hereby declare that the following` is a full and complete. description of the construction and operation of. the same, reference being had to the` accompanying drawings,

making a part of this specification, in which- Figure 1 is a side view. V Figure' 2 is a longitudinal vertical section. Figure 3 is a detached section. Like letters refer to like parts in the 4several views. The nature of my invention relates to an'adjustable chucking mandrel for the purpose of boring out cylin` ders,` turning the outside of cylinders, packing rings, dc., constructed as hereinafter described. When the; l

mandrel is in operation, it is hung upon the ordinary centre of a lathe and revolved from'the head block,` or by other similarmeans.V From the cylinder, A, extend eight sockets, B, two on each side opposite cach other these sockets are tubular and connected to thevcylinder, which receive the arms or slides C, each pair of arms` being attached to" the cross-bar, D, and the lower ends rest upon the head of the screws E, as seen in iig. 2.

The screws E pass through the lower end of the socket and screw into a slide F. Each of these slides is fitted into a dovetail groovel G, in the centres H, as shown in figs. 2 and 3, so as toallow the centres tomove` later-1 p ally in the cylinder. The sides of the grooves are parallel to each other, but the bottom upon whichthe slides` rest are tapering corresponding to the taper of the head, I, of the centre. J andK representenlarged portions of the centres, which :till up and fit lclosely to the bore of the cylinder, so as to have the parts work firmly together. At the outer ends of the centres are screws; on each is fitted a nut, M, figs. 1 and 2. Near the'` middle of the cylinder is placed a gib, N, iig. 2, which extends or `laps on to* the enlargements K, one side of` which being cnt away to receive the ends of the gib. The set-screw O passes through the cylinder and presses upon the gib, by which means the inside ends of the centres are irmly secured in place with the cylinder.

is an auxiliary centre bush tted to the cavity of -the centre, and which is placed upon the dead centre of the. i lathe or machine operating the'mandrel. By these means the main centres are prevented fromnwearing as the p centre bush turns with the mandrel upon the dead centre. When the centre bush is worn out a new olie caiil p replace it without injury to the main centre, which is thereby kept true at all times. In turning the outside oi p. lrings, cylinders, tc., the mandrel is passed into the bore of the same, so that the article will hang or rest .l

upon the bars, D;` this leaves the outsidev free from obstruction for being turned. If the barsl are `to `be` extended to ll the bore, the nuts M are turned back from the ends of the cylinder, and then by means of` the centre and screw mandrel oi' the foot-rest the centres H H are forced toward each other in the cylinder.`

YBy these means,and the action of the inclined groovesG in the tapering head I, thesarmsC are forced out bythe ,p p i screws E en all sides, and at the same time uniformly and simultaneously, as these planes 0f the grooves all` coincide with each other for this purpose, and also for contracting the mandrel for smaller bores. When it is., p

desired to contract the mandrel, the nuts M are screwed up against the endslof the cylinders; which withdraw` the centres from each other, and the dead centre of the foot-block being withdrawn ,also in `the same degree tol :allow the centres H H to recede. In casethe mandrel is to t a tapering bore, Vonly one-:of the nuts` M needbe i released, and either side of the mandrel may be expanded or contracted in theway before described, while the` y Vopposite centre need not be disturbed. The cross-bar D is so connected to the `arms C, by means of apin or` l bolt, as to allow the mandrel to iit a tapering bore by adjusting either end for the purpose as stated. l'fbrrthle` purpose of more firmly securing all the parts together when in operation, the set-,screws Qare` screwed in'to the` slides, and in the sockets B are set-screws R, to aid in holding the arms() in place when set. In` boring ont` 'cylinders the cutter or tool is fastened to the cross-bars by any desirable means, or a cutterhead may be` secured `to the mandrel. For all these uses the mandrel is expanded and contracted in the same way.`

What I claim as my improvement, and desire to secure by Letters Patent, is` i 1. |The grooved centres H, in combination with thev cylinder Aand nutsM, substantially and for the` purpose set `forth. p

2. The cylinder A and sockets B, in combination with the arms C and bars D, substantially asand forthe` 1 purpose described.

3. The grooved centres H and slides F, in combination with the screws E, sockets B, and armsC, ,substan` tially as and for the'purpose specified.

. 4. The gib N and' centres H, in combination with the set-screws O and cylinder A, as and for the purpose set forth. p

PHILO MAL'LIBY.`

Witnesses:

W. H. Bussines, E. E. WAITE. 

